Yes. Hoiliuk has more tones, more tone sandhi, and more phonemes.Thanks Ah-bin! If I'm not mistaken, 海陸 is that Hakka variant with some phonemes not present on Siyen variant, right? My initial reason for learning Hakka was because one year and a half ago I accidentally bought a The Little Prince in Hakka (in the cover there was written in big letters "客家語小王子"). But now, since I found out many Taiwanese people in the Taiwanese association I go whenever I go visit the Taiwanese old lady are actually Hakkas, it'd be nice to learn at least some basics. The old lady is Hoklo, but she speaks Hakka too But the problem is that there's so much dialectal variation in Hakka even in Taiwan and I don't know where they're from, so I don't dare to risk even a greeting in Hakka
That Little Prince is written in Si-yen Hakka. Actually the different types of Si-yen aren't that divergent, and the ambassador of the Republic of China in Australia was a Hakka from taoyuan, and he understood my not-used-for seven-years Si-yen Hakka very well. On the other hand I've had Malaysian Hakkas give me blank looks while others understood, and a Hakka guy from Surinam give me not much reaction at all (Sim knows who I'm talking about!) but was probably more to do with his personality!
Hey...I'll send you a copy of a Hakka book with sound files in Hoiliuk AND Si-yen and see what you think. It is 100 basic sentences in each version.